Can't find SMTP address

On October 14 AT&T shut down the SMTP server (mail.bellsouth.net) which I had been using with my Thunderbird email client for many years. They made all AT&T customers (I use AT&T DSL) switch to SMTP outbound.att.net. By calling AT&T tech. support I was able to have them change my Thunderbird SMTP address to outbound.att.net and it worked for my att.net email address.

Of course all my incoming (POP3) emails are retrieved by Thunderbird.

However, I have six (6) "non" AT&T email addresses. Five with localnet.com and one with a GoDaddy (reynard.name). Changing the SMTP setting to outbound.att.net didn't work. The server gave me an error message.

After three days and as many phone calls to AT&T tech the support the tech switched me to a supervisor (because he didn't know how to solve my problem) and the supervisor, after telling me that AT&T did not support Thunderbird admitted it was not a Thunderbird problem but the "problem" was that AT&T SMTP servers would no longer accept any From: emails that were not an att.net email.

Both localnet and GoDaddy email SMTP servers will only allow connection via their web mail. So I have no SMTP server address to put into my Thunderbird for those email addresses.

Can you help (please) or am I going to have to "bow" to AT&T restrictions and cancel all my "non" email accounts and create att.net addresses or after many, many years of using Thunderbird, start using those stupid web mail facilities.

Thanks,

Robert Reynard